Crop growers oftentimes have a need to apply liquid agricultural chemicals, such as pesticides, herbicides, fertilizers and the like to their growing crops. Typically, the application of agricultural chemicals to growing crops is accomplished by the use of spray implements propelled across the crop fields by an agricultural tractor.
Environmental-protection and cost-containment concerns require that agricultural chemicals be applied in controlled amounts to the growing crops. Thus, spray implements which are provided for the purpose of applying liquid agricultural chemicals to growing crops usually are provided with manually-actuated flow controls so that the tractor operator can stop/start the spray of agricultural chemicals as desired during the chemical application process. (See, U.S. Pat. Nos. 3,905,523 and 3,921,907, the entire content of each being incorporated hereinto expressly by reference.) However, since the flow control is separate from the lift arm control, tractor operators will sometimes forget to stop the spray of agricultural chemicals when making a turn onto a new crop row because the spray implement itself will usually need to be raised before the tractor turns. Also, the tractor operation may sometimes be late in starting the spray when starting the pass down the new crop row. In the former situation, excess agricultural chemicals will be applied to the environment, while in the latter situation not all of the growing crops will be treated by the agricultural chemicals.
According to the present invention, however, automated flow control of the agricultural chemical spray is provided in response to the spray implement being raised and lowered. Thus, according to the present invention, an actuator assembly is provided which senses whether the spray implement is in the raised or lowered position and, in response to such sensed position, disables or enables the flow of liquid agricultural chemical to the spray implement. Since tractor operators will raise the spray implement when making a turn onto a new crop row, and lower the spray implement as the tractor becomes aligned with the new crop row, the actuator assembly according to the present invention lessens the work load on the tractor operator during crop row turns since chemical spray flow control is actuated concurrently and automatically with operation of the spray implement. Thus, more efficient application of the agricultural chemicals results.
Further aspects and advantages of this invention will become more clear after careful consideration is given to the detailed description of the preferred exemplary embodiments thereof which follows.